If you use the “Show in Groups” feature and you have some files with non-ASCII names, you might be able to help us with a fix for next month’s bug fix release. Currently, some things do not quite work right, see the left side of the screenshot below. We have a patch that makes it look like the right side, but I would like to make sure that we don’t break anything in the 4.10 branch. Feel free to download the patch from the review request, and report any regressions there or in the bug report. Thanks.

First of all, I haven’t written the original grouping code myself. What I’m trying to do at the moment is find a simple way to fix some inconsistencies which result in a rather broken grouping (see left half of the screenshot).

It seems that in some languages/locales, a, o, u and their respective umlaut are mostly considered “the same kind of letter”. The current code tries to group them together if and only if the locale-aware sorting puts the umlaut, e.g., ä, in between a and b.

This might still result in unexpected results in some locales, but I think that it will not be worse after the patch than before. Further improvements definitely make sense, but considering how many open bugs we have, how few bug reports we got for incorrect grouping (exactly one AFAIK, the one I’m trying to address here), and how much time our volunteer team of developers can spend on Dolphin, this will probably not happen in the near future.